﻿
namespace Abc.Base;

public class FileContentType
{
    private static IDictionary<string, string> _mappings = new Dictionary<string, string>(StringComparer.InvariantCultureIgnoreCase) {

           #region Big freaking list of mime types

           // combination of values from Windows 7 Registry and
           // from C:\Windows\System32\inetsrv\config\applicationHost.config
           // some added, including .7z and .dat
           {".323", "text/h323"},
           {".3g2", "video/3gpp2"},
           {".3gp", "video/3gpp"},
           {".3gp2", "video/3gpp2"},
           {".3gpp", "video/3gpp"},
           {".7z", "application/x-7z-compressed"},
           {".aa", "audio/audible"},
           {".AAC", "audio/aac"},
           {".aaf", "application/octet-stream"},
           {".aax", "audio/vnd.audible.aax"},
           {".ac3", "audio/ac3"},
           {".aca", "application/octet-stream"},
           {".accda", "application/msaccess.addin"},
           {".accdb", "application/msaccess"},
           {".accdc", "application/msaccess.cab"},
           {".accde", "application/msaccess"},
           {".accdr", "application/msaccess.runtime"},
           {".accdt", "application/msaccess"},
           {".accdw", "application/msaccess.webapplication"},
           {".accft", "application/msaccess.ftemplate"},
           {".acx", "application/internet-property-stream"},
           {".AddIn", "text/xml"},
           {".ade", "application/msaccess"},
           {".adobebridge", "application/x-bridge-url"},
           {".adp", "application/msaccess"},
           {".ADT", "audio/vnd.dlna.adts"},
           {".ADTS", "audio/aac"},
           {".afm", "application/octet-stream"},
           {".ai", "application/postscript"},
           {".aif", "audio/x-aiff"},
           {".aifc", "audio/aiff"},
           {".aiff", "audio/aiff"},
           {".air", "application/vnd.adobe.air-application-installer-package+zip"},
           {".amc", "application/x-mpeg"},
           {".application", "application/x-ms-application"},
           {".art", "image/x-jg"},
           {".asa", "application/xml"},
           {".asax", "application/xml"},
           {".ascx", "application/xml"},
           {".asd", "application/octet-stream"},
           {".asf", "video/x-ms-asf"},
           {".ashx", "application/xml"},
           {".asi", "application/octet-stream"},
           {".asm", "text/plain"},
           {".asmx", "application/xml"},
           {".aspx", "application/xml"},
           {".asr", "video/x-ms-asf"},
           {".asx", "video/x-ms-asf"},
           {".atom", "application/atom+xml"},
           {".au", "audio/basic"},
           {".avi", "video/x-msvideo"},
           {".axs", "application/olescript"},
           {".bas", "text/plain"},
           {".bcpio", "application/x-bcpio"},
           {".bin", "application/octet-stream"},
           {".bmp", "image/bmp"},
           {".c", "text/plain"},
           {".cab", "application/octet-stream"},
           {".caf", "audio/x-caf"},
           {".calx", "application/vnd.ms-office.calx"},
           {".cat", "application/vnd.ms-pki.seccat"},
           {".cc", "text/plain"},
           {".cd", "text/plain"},
           {".cdda", "audio/aiff"},
           {".cdf", "application/x-cdf"},
           {".cer", "application/x-x509-ca-cert"},
           {".chm", "application/octet-stream"},
           {".class", "application/x-java-applet"},
           {".clp", "application/x-msclip"},
           {".cmx", "image/x-cmx"},
           {".cnf", "text/plain"},
           {".cod", "image/cis-cod"},
           {".config", "application/xml"},
           {".contact", "text/x-ms-contact"},
           {".coverage", "application/xml"},
           {".cpio", "application/x-cpio"},
           {".cpp", "text/plain"},
           {".crd", "application/x-mscardfile"},
           {".crl", "application/pkix-crl"},
           {".crt", "application/x-x509-ca-cert"},
           {".cs", "text/plain"},
           {".csdproj", "text/plain"},
           {".csh", "application/x-csh"},
           {".csproj", "text/plain"},
           {".css", "text/css"},
           {".csv", "text/csv"},
           {".cur", "application/octet-stream"},
           {".cxx", "text/plain"},
           {".dat", "application/octet-stream"},
           {".datasource", "application/xml"},
           {".dbproj", "text/plain"},
           {".dcr", "application/x-director"},
           {".def", "text/plain"},
           {".deploy", "application/octet-stream"},
           {".der", "application/x-x509-ca-cert"},
           {".dgml", "application/xml"},
           {".dib", "image/bmp"},
           {".dif", "video/x-dv"},
           {".dir", "application/x-director"},
           {".disco", "text/xml"},
           {".dll", "application/x-msdownload"},
           {".dll.config", "text/xml"},
           {".dlm", "text/dlm"},
           {".doc", "application/msword"},
           {".docm", "application/vnd.ms-word.document.macroEnabled.12"},
           {".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
           {".dot", "application/msword"},
           {".dotm", "application/vnd.ms-word.template.macroEnabled.12"},
           {".dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
           {".dsp", "application/octet-stream"},
           {".dsw", "text/plain"},
           {".dtd", "text/xml"},
           {".dtsConfig", "text/xml"},
           {".dv", "video/x-dv"},
           {".dvi", "application/x-dvi"},
           {".dwf", "drawing/x-dwf"},
           {".dwp", "application/octet-stream"},
           {".dxr", "application/x-director"},
           {".eml", "message/rfc822"},
           {".emz", "application/octet-stream"},
           {".eot", "application/octet-stream"},
           {".eps", "application/postscript"},
           {".etl", "application/etl"},
           {".etx", "text/x-setext"},
           {".evy", "application/envoy"},
           {".exe", "application/octet-stream"},
           {".exe.config", "text/xml"},
           {".fdf", "application/vnd.fdf"},
           {".fif", "application/fractals"},
           {".filters", "Application/xml"},
           {".fla", "application/octet-stream"},
           {".flr", "x-world/x-vrml"},
           {".flv", "video/x-flv"},
           {".fsscript", "application/fsharp-script"},
           {".fsx", "application/fsharp-script"},
           {".generictest", "application/xml"},
           {".gif", "image/gif"},
           {".group", "text/x-ms-group"},
           {".gsm", "audio/x-gsm"},
           {".gtar", "application/x-gtar"},
           {".gz", "application/x-gzip"},
           {".h", "text/plain"},
           {".hdf", "application/x-hdf"},
           {".hdml", "text/x-hdml"},
           {".hhc", "application/x-oleobject"},
           {".hhk", "application/octet-stream"},
           {".hhp", "application/octet-stream"},
           {".hlp", "application/winhlp"},
           {".hpp", "text/plain"},
           {".hqx", "application/mac-binhex40"},
           {".hta", "application/hta"},
           {".htc", "text/x-component"},
           {".htm", "text/html"},
           {".html", "text/html"},
           {".htt", "text/webviewhtml"},
           {".hxa", "application/xml"},
           {".hxc", "application/xml"},
           {".hxd", "application/octet-stream"},
           {".hxe", "application/xml"},
           {".hxf", "application/xml"},
           {".hxh", "application/octet-stream"},
           {".hxi", "application/octet-stream"},
           {".hxk", "application/xml"},
           {".hxq", "application/octet-stream"},
           {".hxr", "application/octet-stream"},
           {".hxs", "application/octet-stream"},
           {".hxt", "text/html"},
           {".hxv", "application/xml"},
           {".hxw", "application/octet-stream"},
           {".hxx", "text/plain"},
           {".i", "text/plain"},
           {".ico", "image/x-icon"},
           {".ics", "application/octet-stream"},
           {".idl", "text/plain"},
           {".ief", "image/ief"},
           {".iii", "application/x-iphone"},
           {".inc", "text/plain"},
           {".inf", "application/octet-stream"},
           {".inl", "text/plain"},
           {".ins", "application/x-internet-signup"},
           {".ipa", "application/x-itunes-ipa"},
           {".ipg", "application/x-itunes-ipg"},
           {".ipproj", "text/plain"},
           {".ipsw", "application/x-itunes-ipsw"},
           {".iqy", "text/x-ms-iqy"},
           {".isp", "application/x-internet-signup"},
           {".ite", "application/x-itunes-ite"},
           {".itlp", "application/x-itunes-itlp"},
           {".itms", "application/x-itunes-itms"},
           {".itpc", "application/x-itunes-itpc"},
           {".IVF", "video/x-ivf"},
           {".jar", "application/java-archive"},
           {".java", "application/octet-stream"},
           {".jck", "application/liquidmotion"},
           {".jcz", "application/liquidmotion"},
           {".jfif", "image/pjpeg"},
           {".jnlp", "application/x-java-jnlp-file"},
           {".jpb", "application/octet-stream"},
           {".jpe", "image/jpeg"},
           {".jpeg", "image/jpeg"},
           {".jpg", "image/jpeg"},
           {".js", "application/x-javascript"},
           {".jsx", "text/jscript"},
           {".jsxbin", "text/plain"},
           {".latex", "application/x-latex"},
           {".library-ms", "application/windows-library+xml"},
           {".lit", "application/x-ms-reader"},
           {".loadtest", "application/xml"},
           {".lpk", "application/octet-stream"},
           {".lsf", "video/x-la-asf"},
           {".lst", "text/plain"},
           {".lsx", "video/x-la-asf"},
           {".lzh", "application/octet-stream"},
           {".m13", "application/x-msmediaview"},
           {".m14", "application/x-msmediaview"},
           {".m1v", "video/mpeg"},
           {".m2t", "video/vnd.dlna.mpeg-tts"},
           {".m2ts", "video/vnd.dlna.mpeg-tts"},
           {".m2v", "video/mpeg"},
           {".m3u", "audio/x-mpegurl"},
           {".m3u8", "audio/x-mpegurl"},
           {".m4a", "audio/m4a"},
           {".m4b", "audio/m4b"},
           {".m4p", "audio/m4p"},
           {".m4r", "audio/x-m4r"},
           {".m4v", "video/x-m4v"},
           {".mac", "image/x-macpaint"},
           {".mak", "text/plain"},
           {".man", "application/x-troff-man"},
           {".manifest", "application/x-ms-manifest"},
           {".map", "text/plain"},
           {".master", "application/xml"},
           {".mda", "application/msaccess"},
           {".mdb", "application/x-msaccess"},
           {".mde", "application/msaccess"},
           {".mdp", "application/octet-stream"},
           {".me", "application/x-troff-me"},
           {".mfp", "application/x-shockwave-flash"},
           {".mht", "message/rfc822"},
           {".mhtml", "message/rfc822"},
           {".mid", "audio/mid"},
           {".midi", "audio/mid"},
           {".mix", "application/octet-stream"},
           {".mk", "text/plain"},
           {".mmf", "application/x-smaf"},
           {".mno", "text/xml"},
           {".mny", "application/x-msmoney"},
           {".mod", "video/mpeg"},
           {".mov", "video/quicktime"},
           {".movie", "video/x-sgi-movie"},
           {".mp2", "video/mpeg"},
           {".mp2v", "video/mpeg"},
           {".mp3", "audio/mpeg"},
           {".mp4", "video/mp4"},
           {".mp4v", "video/mp4"},
           {".mpa", "video/mpeg"},
           {".mpe", "video/mpeg"},
           {".mpeg", "video/mpeg"},
           {".mpf", "application/vnd.ms-mediapackage"},
           {".mpg", "video/mpeg"},
           {".mpp", "application/vnd.ms-project"},
           {".mpv2", "video/mpeg"},
           {".mqv", "video/quicktime"},
           {".ms", "application/x-troff-ms"},
           {".msi", "application/octet-stream"},
           {".mso", "application/octet-stream"},
           {".mts", "video/vnd.dlna.mpeg-tts"},
           {".mtx", "application/xml"},
           {".mvb", "application/x-msmediaview"},
           {".mvc", "application/x-miva-compiled"},
           {".mxp", "application/x-mmxp"},
           {".nc", "application/x-netcdf"},
           {".nsc", "video/x-ms-asf"},
           {".nws", "message/rfc822"},
           {".ocx", "application/octet-stream"},
           {".oda", "application/oda"},
           {".odc", "text/x-ms-odc"},
           {".odh", "text/plain"},
           {".odl", "text/plain"},
           {".odp", "application/vnd.oasis.opendocument.presentation"},
           {".ods", "application/oleobject"},
           {".odt", "application/vnd.oasis.opendocument.text"},
           {".one", "application/onenote"},
           {".onea", "application/onenote"},
           {".onepkg", "application/onenote"},
           {".onetmp", "application/onenote"},
           {".onetoc", "application/onenote"},
           {".onetoc2", "application/onenote"},
           {".orderedtest", "application/xml"},
           {".osdx", "application/opensearchdescription+xml"},
           {".p10", "application/pkcs10"},
           {".p12", "application/x-pkcs12"},
           {".p7b", "application/x-pkcs7-certificates"},
           {".p7c", "application/pkcs7-mime"},
           {".p7m", "application/pkcs7-mime"},
           {".p7r", "application/x-pkcs7-certreqresp"},
           {".p7s", "application/pkcs7-signature"},
           {".pbm", "image/x-portable-bitmap"},
           {".pcast", "application/x-podcast"},
           {".pct", "image/pict"},
           {".pcx", "application/octet-stream"},
           {".pcz", "application/octet-stream"},
           {".pdf", "application/pdf"},
           {".pfb", "application/octet-stream"},
           {".pfm", "application/octet-stream"},
           {".pfx", "application/x-pkcs12"},
           {".pgm", "image/x-portable-graymap"},
           {".pic", "image/pict"},
           {".pict", "image/pict"},
           {".pkgdef", "text/plain"},
           {".pkgundef", "text/plain"},
           {".pko", "application/vnd.ms-pki.pko"},
           {".pls", "audio/scpls"},
           {".pma", "application/x-perfmon"},
           {".pmc", "application/x-perfmon"},
           {".pml", "application/x-perfmon"},
           {".pmr", "application/x-perfmon"},
           {".pmw", "application/x-perfmon"},
           {".png", "image/png"},
           {".pnm", "image/x-portable-anymap"},
           {".pnt", "image/x-macpaint"},
           {".pntg", "image/x-macpaint"},
           {".pnz", "image/png"},
           {".pot", "application/vnd.ms-powerpoint"},
           {".potm", "application/vnd.ms-powerpoint.template.macroEnabled.12"},
           {".potx", "application/vnd.openxmlformats-officedocument.presentationml.template"},
           {".ppa", "application/vnd.ms-powerpoint"},
           {".ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12"},
           {".ppm", "image/x-portable-pixmap"},
           {".pps", "application/vnd.ms-powerpoint"},
           {".ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
           {".ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
           {".ppt", "application/vnd.ms-powerpoint"},
           {".pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
           {".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
           {".prf", "application/pics-rules"},
           {".prm", "application/octet-stream"},
           {".prx", "application/octet-stream"},
           {".ps", "application/postscript"},
           {".psc1", "application/PowerShell"},
           {".psd", "application/octet-stream"},
           {".psess", "application/xml"},
           {".psm", "application/octet-stream"},
           {".psp", "application/octet-stream"},
           {".pub", "application/x-mspublisher"},
           {".pwz", "application/vnd.ms-powerpoint"},
           {".qht", "text/x-html-insertion"},
           {".qhtm", "text/x-html-insertion"},
           {".qt", "video/quicktime"},
           {".qti", "image/x-quicktime"},
           {".qtif", "image/x-quicktime"},
           {".qtl", "application/x-quicktimeplayer"},
           {".qxd", "application/octet-stream"},
           {".ra", "audio/x-pn-realaudio"},
           {".ram", "audio/x-pn-realaudio"},
           {".rar", "application/octet-stream"},
           {".ras", "image/x-cmu-raster"},
           {".rat", "application/rat-file"},
           {".rc", "text/plain"},
           {".rc2", "text/plain"},
           {".rct", "text/plain"},
           {".rdlc", "application/xml"},
           {".resx", "application/xml"},
           {".rf", "image/vnd.rn-realflash"},
           {".rgb", "image/x-rgb"},
           {".rgs", "text/plain"},
           {".rm", "application/vnd.rn-realmedia"},
           {".rmi", "audio/mid"},
           {".rmp", "application/vnd.rn-rn_music_package"},
           {".roff", "application/x-troff"},
           {".rpm", "audio/x-pn-realaudio-plugin"},
           {".rqy", "text/x-ms-rqy"},
           {".rtf", "application/rtf"},
           {".rtx", "text/richtext"},
           {".ruleset", "application/xml"},
           {".s", "text/plain"},
           {".safariextz", "application/x-safari-safariextz"},
           {".scd", "application/x-msschedule"},
           {".sct", "text/scriptlet"},
           {".sd2", "audio/x-sd2"},
           {".sdp", "application/sdp"},
           {".sea", "application/octet-stream"},
           {".searchConnector-ms", "application/windows-search-connector+xml"},
           {".setpay", "application/set-payment-initiation"},
           {".setreg", "application/set-registration-initiation"},
           {".settings", "application/xml"},
           {".sgimb", "application/x-sgimb"},
           {".sgml", "text/sgml"},
           {".sh", "application/x-sh"},
           {".shar", "application/x-shar"},
           {".shtml", "text/html"},
           {".sit", "application/x-stuffit"},
           {".sitemap", "application/xml"},
           {".skin", "application/xml"},
           {".sldm", "application/vnd.ms-powerpoint.slide.macroEnabled.12"},
           {".sldx", "application/vnd.openxmlformats-officedocument.presentationml.slide"},
           {".slk", "application/vnd.ms-excel"},
           {".sln", "text/plain"},
           {".slupkg-ms", "application/x-ms-license"},
           {".smd", "audio/x-smd"},
           {".smi", "application/octet-stream"},
           {".smx", "audio/x-smd"},
           {".smz", "audio/x-smd"},
           {".snd", "audio/basic"},
           {".snippet", "application/xml"},
           {".snp", "application/octet-stream"},
           {".sol", "text/plain"},
           {".sor", "text/plain"},
           {".spc", "application/x-pkcs7-certificates"},
           {".spl", "application/futuresplash"},
           {".src", "application/x-wais-source"},
           {".srf", "text/plain"},
           {".SSISDeploymentManifest", "text/xml"},
           {".ssm", "application/streamingmedia"},
           {".sst", "application/vnd.ms-pki.certstore"},
           {".stl", "application/vnd.ms-pki.stl"},
           {".sv4cpio", "application/x-sv4cpio"},
           {".sv4crc", "application/x-sv4crc"},
           {".svc", "application/xml"},
           {".swf", "application/x-shockwave-flash"},
           {".t", "application/x-troff"},
           {".tar", "application/x-tar"},
           {".tcl", "application/x-tcl"},
           {".testrunconfig", "application/xml"},
           {".testsettings", "application/xml"},
           {".tex", "application/x-tex"},
           {".texi", "application/x-texinfo"},
           {".texinfo", "application/x-texinfo"},
           {".tgz", "application/x-compressed"},
           {".thmx", "application/vnd.ms-officetheme"},
           {".thn", "application/octet-stream"},
           {".tif", "image/tiff"},
           {".tiff", "image/tiff"},
           {".tlh", "text/plain"},
           {".tli", "text/plain"},
           {".toc", "application/octet-stream"},
           {".tr", "application/x-troff"},
           {".trm", "application/x-msterminal"},
           {".trx", "application/xml"},
           {".ts", "video/vnd.dlna.mpeg-tts"},
           {".tsv", "text/tab-separated-values"},
           {".ttf", "application/octet-stream"},
           {".tts", "video/vnd.dlna.mpeg-tts"},
           {".txt", "text/plain"},
           {".u32", "application/octet-stream"},
           {".uls", "text/iuls"},
           {".user", "text/plain"},
           {".ustar", "application/x-ustar"},
           {".vb", "text/plain"},
           {".vbdproj", "text/plain"},
           {".vbk", "video/mpeg"},
           {".vbproj", "text/plain"},
           {".vbs", "text/vbscript"},
           {".vcf", "text/x-vcard"},
           {".vcproj", "Application/xml"},
           {".vcs", "text/plain"},
           {".vcxproj", "Application/xml"},
           {".vddproj", "text/plain"},
           {".vdp", "text/plain"},
           {".vdproj", "text/plain"},
           {".vdx", "application/vnd.ms-visio.viewer"},
           {".vml", "text/xml"},
           {".vscontent", "application/xml"},
           {".vsct", "text/xml"},
           {".vsd", "application/vnd.visio"},
           {".vsi", "application/ms-vsi"},
           {".vsix", "application/vsix"},
           {".vsixlangpack", "text/xml"},
           {".vsixmanifest", "text/xml"},
           {".vsmdi", "application/xml"},
           {".vspscc", "text/plain"},
           {".vss", "application/vnd.visio"},
           {".vsscc", "text/plain"},
           {".vssettings", "text/xml"},
           {".vssscc", "text/plain"},
           {".vst", "application/vnd.visio"},
           {".vstemplate", "text/xml"},
           {".vsto", "application/x-ms-vsto"},
           {".vsw", "application/vnd.visio"},
           {".vsx", "application/vnd.visio"},
           {".vtx", "application/vnd.visio"},
           {".wav", "audio/wav"},
           {".wave", "audio/wav"},
           {".wax", "audio/x-ms-wax"},
           {".wbk", "application/msword"},
           {".wbmp", "image/vnd.wap.wbmp"},
           {".wcm", "application/vnd.ms-works"},
           {".wdb", "application/vnd.ms-works"},
           {".wdp", "image/vnd.ms-photo"},
           {".webarchive", "application/x-safari-webarchive"},
           {".webtest", "application/xml"},
           {".wiq", "application/xml"},
           {".wiz", "application/msword"},
           {".wks", "application/vnd.ms-works"},
           {".WLMP", "application/wlmoviemaker"},
           {".wlpginstall", "application/x-wlpg-detect"},
           {".wlpginstall3", "application/x-wlpg3-detect"},
           {".wm", "video/x-ms-wm"},
           {".wma", "audio/x-ms-wma"},
           {".wmd", "application/x-ms-wmd"},
           {".wmf", "application/x-msmetafile"},
           {".wml", "text/vnd.wap.wml"},
           {".wmlc", "application/vnd.wap.wmlc"},
           {".wmls", "text/vnd.wap.wmlscript"},
           {".wmlsc", "application/vnd.wap.wmlscriptc"},
           {".wmp", "video/x-ms-wmp"},
           {".wmv", "video/x-ms-wmv"},
           {".wmx", "video/x-ms-wmx"},
           {".wmz", "application/x-ms-wmz"},
           {".wpl", "application/vnd.ms-wpl"},
           {".wps", "application/vnd.ms-works"},
           {".wri", "application/x-mswrite"},
           {".wrl", "x-world/x-vrml"},
           {".wrz", "x-world/x-vrml"},
           {".wsc", "text/scriptlet"},
           {".wsdl", "text/xml"},
           {".wvx", "video/x-ms-wvx"},
           {".x", "application/directx"},
           {".xaf", "x-world/x-vrml"},
           {".xaml", "application/xaml+xml"},
           {".xap", "application/x-silverlight-app"},
           {".xbap", "application/x-ms-xbap"},
           {".xbm", "image/x-xbitmap"},
           {".xdr", "text/plain"},
           {".xht", "application/xhtml+xml"},
           {".xhtml", "application/xhtml+xml"},
           {".xla", "application/vnd.ms-excel"},
           {".xlam", "application/vnd.ms-excel.addin.macroEnabled.12"},
           {".xlc", "application/vnd.ms-excel"},
           {".xld", "application/vnd.ms-excel"},
           {".xlk", "application/vnd.ms-excel"},
           {".xll", "application/vnd.ms-excel"},
           {".xlm", "application/vnd.ms-excel"},
           {".xls", "application/vnd.ms-excel"},
           {".xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
           {".xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12"},
           {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
           {".xlt", "application/vnd.ms-excel"},
           {".xltm", "application/vnd.ms-excel.template.macroEnabled.12"},
           {".xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
           {".xlw", "application/vnd.ms-excel"},
           {".xml", "text/xml"},
           {".xmta", "application/xml"},
           {".xof", "x-world/x-vrml"},
           {".XOML", "text/plain"},
           {".xpm", "image/x-xpixmap"},
           {".xps", "application/vnd.ms-xpsdocument"},
           {".xrm-ms", "text/xml"},
           {".xsc", "application/xml"},
           {".xsd", "text/xml"},
           {".xsf", "text/xml"},
           {".xsl", "text/xml"},
           {".xslt", "text/xml"},
           {".xsn", "application/octet-stream"},
           {".xss", "application/xml"},
           {".xtp", "application/octet-stream"},
           {".xwd", "image/x-xwindowdump"},
           {".z", "application/x-compress"},
           {".zip", "application/x-zip-compressed"},
           #endregion Big freaking list of mime types
    };

    /// <summary>
    /// 获取文件MimeType
    /// </summary>
    /// <param name="extension"></param>
    /// <returns></returns>
    /// <exception cref="ArgumentNullException"></exception>
    public static string GetMimeType(string extension)
    {
        if (extension == null)
        {
            throw new ArgumentNullException("extension");
        }

        if (!extension.StartsWith("."))
        {
            extension = "." + extension;
        }

        string mime;

        return _mappings.TryGetValue(extension, out mime) ? mime : "application/octet-stream";
    }

    ///// <summary>
    ///// 获取文件MimeType
    ///// </summary>
    ///// <param name="fileName">文件名</param>
    ///// <returns></returns>
    //public static string GetFileMimeType(this string fileName)
    //{
    //    var extname = fileName[fileName.LastIndexOf(".")..]; //扩展名，如.jpg
    //    return GetMimeType(extname);
    //}
}